urtication vs roseola

urtication and roseola both are nouns.

Word	Noun	Adjective	Verb	Adverb
urtication	Yes	No	No	No
roseola	Yes	No	No	No

As nouns, roseola is a hypernym of urtication; that is, roseola is a word with a broader meaning than urtication:

urtication: an itchy skin eruption characterized by weals with pale interiors and well-defined red margins; usually the result of an allergic response to insect bites or food or drugs
roseola: any red eruption of the skin

Other hypernyms of urtication include efflorescence, rash, skin rash, hypersensitivity reaction.

urtication (noun)	roseola (noun)
a sensation of having been stung by nettles	any red eruption of the skin
an itchy skin eruption characterized by weals with pale interiors and well-defined red margins; usually the result of an allergic response to insect bites or food or drugs